[Nusoap-general] Undefined property: operation ...

[<cat...@ca...>]

Hi all,

Am receiving the following error:

Notice: Undefined property: operation in /path/nusoap.php on line 6838

Here's the code I'm using:
-------------------------------------------------------------
$this->soap = new soapclient( 'http://app.campaignmonitor.com/api/api.asmx' );

$body = '<Subscriber.AddWithCustomFields
xmlns="http://app.campaignmonitor.com/api/">';
$body .='<ApiKey>' . $this->settings['APIKey'] . '</ApiKey>';
$body .='<ListID>' . $this->settings['ListID'] . '</ListID>';
$body .='<Email>' . $this->data['email'] . '</Email>';
$body .='<Name>' . $this->data['name'] . '</Name>';
$body .='<CustomFields>';
$body .='<SubscriberCustomField>';
$body .='<Key>[company]</Key><Value>' . $this->data['company'] . '</Value>';
$body .='</SubscriberCustomField>';
$body .='<SubscriberCustomField>';
$body .='<Key>[address]</Key><Value>' . $this->data['address'] . '</Value>';
$body .='</SubscriberCustomField>';
$body .='</CustomFields>';
$body .='</Subscriber.AddWithCustomFields>';

$this->soap->send( $body,
'http://app.campaignmonitor.com/api/Subscriber.AddWithCustomFields' );
-------------------------------------------------------------

Doing a little debugging around line 6838 tells me that ["operations"]=> 
array(0) { }. Looks empty and therefore $this->operation isn't being set.

Any thoughts on what's going on here?

Thanks,
CJ